During this period, the Panzas establish the core of the third collection that would lead them, until Giuseppe’s death, to discover and foster some of the main developments of American and European contemporary art.

From 1990 the collectors become fascinated by monochrome and color in painting. Consequently, they purchase works by Winston Roeth, David Simpson and Phil Sims from the gallery owned by Eric Stark in New York. Other paintings by Roy Thurston, Timothy Litzmann and Michael Rouillard, as well as by women artists such as Anne Appleby, Ruth Ann Fredenthal, Patricia Moisan and Lies Kraal, will follow.

Un choix d’art Minimal dans la collection Panza held at the Musée d’Art Moderne de la Ville de Paris features works by Andre, Flavin, LeWitt, Morris, Nauman, Nonas, Turrell and Weiner (July 12 - November 4, 1990).

Between 1990 and 1992 The Solomon R. Guggenheim Foundation in New York acquires over 350 Minimal, Post-minimal, Conceptual and Light & Space works (along with a ten-year loan of 230 pieces) by Andre, Barry, Brewster, Charlton, Darboven, De Maria, Flavin, Highstein, Huebler, Irwin, Joseph, Judd, Kaiser Vogel, Law, LeWitt, Long, Mangold, Marden, Morris, Nauman, Nordman, Orr, Ryman, Serra, Tivey, Turrell, Webster, Weiner and Wheeler.

From 1991, the collection includes the organic art of Allan Graham, Emil Lukas and Ross Rudel. Along with object-reductionist art by Stuart Arends, Ron Griffin, Roni Horn, Jonathan Seliger and Robert Tiemann, the Panzas gather works by David Goerk and Barry X Ball.

In the early 1990s they put together various works by European artists such as Thomas Schütte, Jan Vercruysse, Frank Gerritz, Hubert Kiecol and Harald Klingelhöller. At the same time, they become interested in the late-Minimalist work of John McCraken and Anne Truitt, and in the Post-Minimalist generation of artists such as Grenville Davey, and later on, Julia Mangold.

In 1992 the Panzas begin purchasing works by Max Cole. While in New York, they meet the painter and sculptor Lawrence Carroll, who was then based in California. They continue being involved in the Los Angeles art scene that includes artists like Gregory Mahoney, Tim Ebner, Greg and Jeff Colson, among others.

The Museo Cantonale d’Arte in Lugano organizes the exhibition Panza di Biumo. Gli anni Ottanta e Novanta dalla Collezione, the first survey to combine artworks from the second and third collection by American and European artists: Kosuth, Le Witt, Darboven, Weiner, Barry, Tim Ebner, Barry X Ball, Tiemann, Beckman, Horn, Lere, Shelton, Thurston, Arends, Spalletti, Webster and A. Graham (April 11 - July 5, 1992).

In 1994 the Getty Research Institute in Los Angeles purchases the Panza archive that comprises materials from 1956 al 1990 - Giuseppe Panza Papers, (Special Collections).  Giuseppe Panza Papers.

Gift to MOCA, Los Angeles of 70 artworks from the third collection created between 1982 and 1993 by 10 California-based artists: Carroll, G. Colson, J. Colson, Griffin, Lere, Mahoney, Rudel, Shelton, Therrien and Thurston.

In 1994-95 the Panzas donate 200 works by Roger Ackling, Arends, Ball, Beckman, Carroll, Fredenthal, A. Graham, Gloria Graham, Griffin, Horn, James Hyde, Kiecol, Klingelhöller, Lere, Daniel Levine, Mahoney, Roeth, Rudel, Erik Saxon, Schütte, Seborovski, Shelton, Simpson, Spalletti, Therrien, Thurston, Tiemann, Vercruysse and Webster to the Museo Cantonale d’Arte in Lugano.

That same institution hosts the exhibition Donazione Panza di Biumo. Arte europea e americana ‘83-’93. Una prima scelta dalle cento opere (March 25 - April 30, 1995). Further shows on the acquisition will be held in 1997, 2000 and 2009.

The Panzas donate Villa Menafoglio Litta Panza to FAI (Fondo per l’Ambiente Italiano). In addition to the building and the park, the gift includes part of the collection of non-Western art, objects, furnishings, and 133 contemporary artworks (augmented in 2005, 2007 and 2009) by Arends, Beckman, Brewster, Carroll, Cole, Flavin, Alfonso Fratteggiani Bianchi, Fredenthal, A. Graham, Irwin, Kiecol, Mangold, McCracken, Nordman, Puryear, Roeth, Rudel, Simpson, Sims, Spalletti, Therrien, Tiemann, Turrell and Webster

Giuseppe develops exhibition plans in view to the Villa’s opening to the public (2000); these include the presentation of Flavin’s fluorescent lights (acquired in 1987) in the Rustici wing.

La collezione Panza di Biumo: artisti degli anni ’80 e ’90 in the 16th-century Palazzo delle Albere in Trento is the first public exhibition of the collection to be held in an Italian historical building (September 12 - December 8).

The space of the Lonja of Palma de Mallorca, an example of late Gothic architecture of limited size, in Collecció Panza di Biumo Anys 80 i 90 (August - September) requires a drastic selection of works and artists. Yet Carroll, Griffin, Schutte, Seborovski, Shelton, Simpson, Sims, Thurston e Vercruysse well represent the main research issues at the time.

The Guggenheim Museums and Art of This Century, opening exhibition of the Guggenheim Bilbao, includes a selection of Minimal and Conceptual art from the collection (October 19, 1997 - June 1st, 1998).

From 1998 to 2003 works by Arends, Beckman, Carroll, Fredenthal, Rudel, Simpson, Sims and Spalletti are lent to the Commission for the Cultural Heritage in Perugia and displayed at the Museo del Palazzo Ducale in Gubbio: La collezione Panza di Biumo. Artisti degli anni ’80-’90 (December 5, 1998 - December 4, 2003).

The exhibition Panza: The Legacy of a Collector organized by the MOCA in Los Angeles comprises for the first time the two parts of the collection acquired in 1984 and 1994 (December 12, 1999 - April 30, 2000).